[PATCH v1 38/55] KVM: PPC: Book3S HV P9: Restrict DSISR canary workaround to processors that require
Nicholas Piggin <[email protected]>
| Newsgroups | org.kernel.vger.kvm-ppc,org.ozlabs.lists.linuxppc-dev |
|---|---|
| Message-ID | <[email protected]> |
Use CPU_FTR_P9_RADIX_PREFETCH_BUG for this, to test for DD2.1 and below processors. -43 cycles (7178) POWER9 virt-mode NULL hcall Signed-off-by: Nicholas Piggin <[email protected]> --- arch/powerpc/kvm/book3s_hv.c | 3 ++- arch/powerpc/kvm/book3s_hv_p9_entry.c | 6 ++++-- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index e7dfc33e2b38..47ccea5ffba2 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1598,7 +1598,8 @@ XXX benchmark guest exits unsigned long vsid; long err; - if (vcpu->arch.fault_dsisr = HDSISR_CANARY) { + if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG) && + unlikely(vcpu->arch.fault_dsisr = HDSISR_CANARY)) { r = RESUME_GUEST; /* Just retry if it's the canary */ break; } diff --git a/arch/powerpc/kvm/book3s_hv_p9_entry.c b/arch/powerpc/kvm/book3s_hv_p9_entry.c index 737d4eaf74bc..d83b5d4d02c1 100644 --- a/arch/powerpc/kvm/book3s_hv_p9_entry.c +++ b/arch/powerpc/kvm/book3s_hv_p9_entry.c @@ -671,9 +671,11 @@ int kvmhv_vcpu_entry_p9(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpc * HDSI which should correctly update the HDSISR the second time HDSI * entry. * - * Just do this on all p9 processors for now. + * The "radix prefetch bug" test can be used to test for this bug, as + * it also exists fo DD2.1 and below. */ - mtspr(SPRN_HDSISR, HDSISR_CANARY); + if (cpu_has_feature(CPU_FTR_P9_RADIX_PREFETCH_BUG)) + mtspr(SPRN_HDSISR, HDSISR_CANARY); mtspr(SPRN_SPRG0, vcpu->arch.shregs.sprg0); mtspr(SPRN_SPRG1, vcpu->arch.shregs.sprg1); -- 2.23.0